Complete Field Guide · How to use surveys without internet
Surveys are built for the field. Work on any site — no internet required. This guide explains how offline caching works, what the status banners mean, and how your changes sync automatically when you're back online.
What actually happens behind the scenes
When you open any survey, all its data is automatically saved to your browser's IndexedDB — a high-capacity local database built into every modern browser. This gives you up to 250 MB of survey storage that persists even when the page is closed or the network is lost.
IndexedDB
Stores floor plans, devices, cable paths, and metadata locally
Auto-Sync
Pushes local changes to the server as soon as you're back online
Offline-first
Reads from local cache first — no waiting for the network
Info: IndexedDB is separate from cookies and localStorage — it's much larger and is not cleared by normal browser history clearing unless you explicitly choose "Site Data".
How to know which surveys have unsaved remote changes
On the Surveys list page, any survey that has local edits not yet pushed to the server shows a small amber "Unsynced" badge next to its status. This badge appears any time you've made changes while offline (or before a sync completes).
Good to know: Unsynced badges clear automatically the moment that survey's data reaches the server — no action required from you.
Important: If you see "Unsynced" badges but no banner, it means you're online but the auto-sync hasn't completed yet. Wait a moment or reload the page.
Typical field workflow
Open the Surveys list page while you still have internet. All surveys load and cache automatically. You don't need to do anything special — just having the page open is enough.
Once you're on site without WiFi or cellular, open the survey you need. The app reads from IndexedDB instantly — no loading spinner, no 'offline' errors.
Place devices, draw cable paths, configure parts, add annotations — every action saves locally as you go. The amber banner reminds you that you're offline, but everything still works.
Hitting Save while offline writes a full snapshot to IndexedDB. This is also the revision checkpoint — it protects against accidental large changes.
When internet returns, the app detects it and automatically begins syncing. A blue banner shows syncing progress, then a green 'synced' confirmation. All Unsynced badges clear.
Tip: You can keep working during the sync — edits you make while the sync runs will be pushed in the next cycle.
What happens when you come back online
The app constantly monitors your network status. The moment it detects a transition from offline → online, it:
Info: Syncing is debounced — rapid consecutive edits are batched into a single push to avoid excessive server requests.
How much can be cached and what happens when it's full
The cache targets 250 MB of storage. Floor plan images are the largest consumers — a high-resolution aerial photo is typically 2–5 MB. The app also requests persistent storage from the browser, which prevents the browser from evicting the cache under memory pressure.
Surveys are cached as you open them. The most recently accessed surveys stay in cache longest.
The oldest clean (already-synced) surveys are automatically pruned to free space. You can still access them — they'll just re-download from the server on next open.
Any survey with local changes not yet on the server is protected from auto-pruning, even if storage is full. Your unsaved work is always preserved.
Important: Large floor plan image files significantly reduce how many surveys fit in the offline cache. Use the Google Maps capture (lower resolution) rather than uploading very large PDFs converted to images.
Best practices for field use on tablets and phones
The Surveys App (accessible at /SurveysApp) is optimized for touch devices and works fully offline.
Recommended devices
iPad, Android tablet, or any touch-screen laptop. The full browser version works on desktop/laptop.
Pre-load surveys on WiFi
Before going to a site with no connectivity, open the Surveys list while on WiFi to cache all data.
Airplane mode test
Try enabling airplane mode and reloading the survey — if it loads, you're fully offline-ready for that survey.
Battery / sleep
Data is safely in IndexedDB even if the device sleeps. Wake and open the survey — your work is there.
Tip: Add the Surveys App to your home screen (PWA) for the fastest offline access and a native app-like experience.
When things don't go as expected
Important: Never clear "Site Data" or "Cookies and site data" in your browser while offline. This deletes IndexedDB and any unsynced changes are permanently lost.
Info: Incognito / Private browsing mode has very limited IndexedDB storage and may not persist between sessions. Use a regular browser window for field work.
Tip: If you suspect an issue, open the survey on a device with internet first — the server version is always the authoritative copy and can be used to re-seed the local cache.
Do I need to do anything to enable offline?
No — just open the survey while online. It caches automatically.
How much storage is available?
Up to 250 MB for all cached surveys combined.
What happens if I lose connection mid-edit?
Continue working — all saves go to IndexedDB instantly.
How do I know a survey is cached offline?
If it loads without a spinner in airplane mode, it's cached.
Will I lose data if I close the browser offline?
No — IndexedDB persists across browser sessions.
What is the 'Unsynced' badge?
Local changes not yet pushed to the server. Clears on reconnect.